Graphitic Carbocatalysts with Pentagon Defects Synthesized from Polyperylene for Electrocatalytic Oxygen Reduction and Flexible Zinc-Air Batteries

Carbocatalysts have been widely explored in renewable energy systems, such as fuel cells and metal-air batteries, and their performance critically hinges upon the intricate balance between their graphitic and defective structures. However, achieving this harmony while preserving high graphitization levels is still a formidable challenge. Herein, an innovative graphitic/defective heteroatom-free carbon nanosheet (GDHfCN) is developed through a dual molten salt chemical treatment of polyperylene, which uniquely marries high-density graphitic structures with abundant pentagon defects. The GDHfCN demonstrates exceptional electrocatalytic performance for oxygen reduction reaction (ORR), with a high half-wave potential of 0.891 V, a low Tafel slope of 52.1 mV dec–1, and a kinetic current density of up to 106.42 mA cm–2. This nanoscale configuration outperforms the catalysts typically synthesized through sole molten salt treatment, which is limited by their focus on either defective or graphitic structures. Moreover, the application of GDHfCN in a flexible zinc-air battery confirms its practical potential, exhibiting remarkable energy density and stability under bending tests. This study not only illustrates the balance of the graphitic and defective structures in carbocatalysts but also advances the field of electrocatalysis, marking a significant stride in the development of high-performance energy devices.